Process for the treatment of synthetic linear polycarbonamide textile fibers



United States Patent 3,153,565 PROCESS FOR THE TREATMENT OF SYNTHETIC LINEAR POLYCARBONAMIDE TEXTILE FIBERS Karl Dithmar and Elfriede Naujoks, Frankfurt am Main,

Germany, assignors to Deutsche Goldund Silber- Scheideanstalt vormals Roessler, Frankfurt am Main, Germany No Drawing. Filed Oct. 13, 1960, Ser. No. 62,325 Claims priority, application Germany, Mar. 12, 1953, D 14,553; Mar. 20, 1954, D 17,356; Nov. 13, 1954, D 19,111; Dec. 11, 1954, D 19,309

1 Claim. (Cl. 8-111) The present invention relates to improvements in preventing damage to textile fibers containing a fiber forming synthetic linear polycarbonamide which has recurring amide groups as integral parts of the main polymer chain when treated with peroxidic bleaching compounds.

It is known that polyamide fibers are strongly attacked when treated in washing and bleaching baths containing peroxide compounds, so that appreciable losses in strength occur. The decrease in strength of the polyamide fibers, for example, of the fibrous materials known under the trade names of Perlon and Nylon, may amount to up to 40 to 80% of the original strength if the action of the peroxide containing washing and bleaching baths is carried out at relatively high temperatures over a relatively long period, which is often necessary, for example, in the treatment of mixed fibrous materials containing polyamide for the purpose of producing an adequate bleaching effect, or if, as is necessary when using detergents containing peroxide, the treatment of the articles containing polyamide has to be repeated at intervals of time when the articles become soiled. The same damage to the fibers occurs even if the peroxide containing bleaching and Washing baths are stabilized in the conventional manner with magnesium silicate or phosphates or other additives which moderate the spontaneous evolution of oxygen.

It has now been found that it is possible to produce a substantial protective action on fibers, spun yarns, woven and knitted fabrics containing synthetic linear polycarbonamides, or articles manufactured therefrom, either alone or together with other fibrous materials during bleaching with peroxide compounds. The peroxide compounds referred to herein include hydrogen peroxide, sodium peroxide, other alkali or alkaline earth metal peroxides, persulphuric acid or its salts, perboric acid or its salts, percarbonic acid or its salts, perphosphoric acid or its salts, or similar compounds which form hydrogen peroxide in acid medium. According to the invention,

materials with peroxide compoundsin h ""eariirfis'i'se arned 6131 iii the P 9meant-oximcspnhygl q 76. T

Illustrative examples ofsuchoxi'fies or hydroxamic acids are:

Oxaldihydroxamic acid HO\ /OH CO x EON NOH 0 0 C-C HOHN NHOH Benzaldoxime 'ice Patented Oct. 20, 1964 Propionic hydroxamic acid /OH CgH5-C\ NOH NHOH Benzhydroxamic acid NOH o Ga NHOH Succinic dialdehyde dioxime H H HON=JJ-CH CH =NOH Succinic diamide dioxime INIYHQ NH HoN=ccHr-oHr 3=NoH Cyclohexanone oxime CHg-CHg OH; C=NOH CHFOHQ The compounds referred to develop their protective effect in the bleaching bath in the presence of peroxides by preventing the attack of the active oxygen on the polycarbonamide fibers. The bleaching or washing baths can contain active oxygen up to a maximum amount of 0.3 mol of H 0 or 0.3 gram atom of active oxygen per liter of bleaching liquid. The protective agents described herein are added in amounts of 0.01 to 0.05 mol per liter. However, certain individual agents are effective even in of this concentration. When used according to instructions, peroxide detergents yield maximum concentrations, of 0.25 g. or 0.016 gram atom of active oxygen per liter. In this case, 0.001 to 0.005 mol of the said protective agents per liter of peroxide detergent bath is sufiicient, while once again individual products provide complete protection of the fibers when used with A of this concentration. They may also be directly incorporated with washing powders to provide peroxide detergent mixtures which in practice do not reduce the tensile strength of polyamide fibers, even when the treatment is repeated several times. The bleaching and washing baths may as customary also contain stabilizers (water glass, magnesium salts or phosphates) and also means for adjusting the pH value and surface active substances. The protective agent can also be products applied in aqueous or alcoholic solution to the polycarbonamide fibers and then dried. The strength of textiles made of polycarbonamide fibers and treated in this manner is scarcely reduced, even after subsequent repeated peroxide treat ment in a bleaching or washing bath which does not contain any protective agent.

Finally, the products may also be used by incorporating them in the Perlon or Nylon substance itself from which the fibers are spun.

The following examples will serve to illustrate several embodiments of the invention.

Example 1 A stranded yarn material consisting of e caprolactam filaments with a titre of 60 deniers was treated in the bath ratio of 1:50 with occasional manipulation, for two hours at a temperature of 60 C. in a bath which contained:

Example 2 e Caprolactam Perlon fabric having a warp and weft both consisting of 60 denier c caprolactam silk was washed for two hours at 90 C. in a washing solution which contained peroxide and to which 0.3 g. of benzaldoxime was added as protective agent per liter of the solution.

The tensile strength of the e caprolactam fabric dropped after this treatment from 45.5 Rkm. to 43.83 Rkm., this corresponding to a strength loss of 3.7%.

The bath had the following composition per liter:

1.0 g. 5.0 g. 0.2 g. 1.5 g. 0.7 g. 1.6 g. 0.3 g.

Rkm.:the number of kilometers of the yarn which will be sustained by the yarn before breaking.

of sodium perborate of soap flakes of dry water glass of calcined soda of sodium bicarbonate of sodium pyrophosphate of a-benzaldoxime Example 3 Stranded material consisting of c caprolactam silk was treated in a bath for 2 hours at a temperature just below boiling point, the material being moved occasionally. The bath had the following composition per liter:

2.5 g. 4.5 g. 0.2 g. 1.2 g. 0.5 g. 1.1 g. 0.5 g.

of sodium perborate of soap powder of dry water glass of calc. soda of sodium bicarbonate of neutral sodium pyrophosphate of propionic hydroxamic acid After being washed by boiling, the strength had dropped from 45.0 to 43.02 Rkm., this being a strength loss of 4.3%, while the strength loss was 31.7% in a comparative test in which no propionic hydroxamic acid was added.

Example 4 A length of e-caprolactam underwear material was subjected to a bleaching treatment for four hours at a temperature of 60 C. in a bath containing hydrogen peroxide.

The bath had the following composition:

4.8 g./liter of active oxygen in the form of hydrogen peroxide (0.3 mol) 0.1 g. of crystallized magnesium sulphate 1.0 cc. of commercially available water glass 1.4 g. of benzhydroxamic acid (0.01 mol) The strength of the e-caprolactam material, which was 45.5 Rkm., prior to the treatment, was reduced to 44.10 Rkm. after the bleaching, this corresponding to a reduction of 3.1%

4 Example 5 A hank of e caprolactam knitting yarn with the metric number 17.1/ 3 was treated for two hours at a temperature of C. in a bath containing:

2.0 g. of sodium perborate 0.1 g. of crystallized magnesium sulphate 1.0 cc. of commercially available water glass 5.0 g. of soap flakes 0.5 g. of succinic dialdehyde dioxime After the treatment, it was established that the reduction in strength was from 29.65 to 27.12 Rkm., this corresponding to a loss of 8.6%.

Example 6 A hank of yarn consisting of e caprolactam and having a titre of 60 deniers was washed for 2 hours at a temperature of about C. in a bath containing per liter:

1.0 g. 5.0 g. 0.2 g. 1.5 g. 0.7 g. 1.6 g. 0.5 g.

of sodium perborate of soap flakes of dry water glass of calc. soda of sodium bicarbonate of sodium pyrophosphate of cyclohexanone oxime The strength of the polyamide silk was lowered from an initial value of 43 Rkm. to 39.15 Rkm., this corresponding to a strength loss of 9.0%

Example 7 A length of material consisting of 60 denier e caprolactam warp and weft was subjected to a washing treatment for two hours at 90 C. The washing bath had the fol lowing composition:

1.0 g. 5.0 g. 0.2 g. 1.5 g. 0.7 g. 1.6 g. 0.5 g.

of sodium perborate of soap flakes of dry water glass of calc. soda of sodium bicarbonate of sodium pyrophosphate of succinic diamide dioxirne The tensile strength of the weft material was reduced from 45.0 Rkm. to 41.49 Rkm., this corresponding to a reduction in strength of 7.8%

Example 8 2O denier endless e caprolactam polyamide (Perlon) silk was treated at a bath ratio of 1:30 at 90 C. with a solution containing 10 g. per liter of a commercial wash ing agent to which oxalic acid diamide oxime had been added as a protective agent.

The washing agent was of the following composition, parts by weight:

Soap Powder 57.0 Caleined soda 15.0 Sodium pyrophosphate 7.5 Sodium tripolyphosphate 7.5 Dry water glass 7.0 Sodium perborate 6.0 Oxalic acid diamide oxime 1.0

The original tensile strength of the e caprolactam filaments was 46.5 Rkm. and was only lowered to 44.8 Rkm. by 2 hours treatment in the bath, this corresponding to a 3.7% loss in strength.

When the same washing agent was employed but without the protective agent, the treated filaments only had a tensile strength of 34.2 Rkm. which corresponded to a 26.5% loss in strength.

Example 9 15 denier monofilament e caprolactam polyamide stocking silk delustered with titanium dioxide was treated at a bath ratio of 1:30 for two hours at 85 C. with a washing bath containing 10 g. per liter of the following washing agent:

Parts by weight Marseilles soap 57.0 Soda 15.0 Pulverized water glass 7.0 Sodium pyrophosphate 7.5 Sodium tripolyphosphate 7.5 Sodium perborate 6.0 Benzhydroxamic acid 2.0

Example 10 Strands of 60 denier glossy e caprolactam polyamide silk were treated for 2 hours at 85 C. in a bath ratio of 1:50 with 1% aqueous solution of the following washing agent:

Parts by weight Soap flakes 42.0 Soda 17.4 Dry water glass 2.6 Trilon BR (chelating agent) 0.4 Cellulose glycolate 0.1

Blankophor BH extra high concentrate (brightener) 0.075 Moisture (from chemicals) 28.425 Sodium perborate 7.0 Succinic diamide dioxime 2.0

The treatment caused a drop in tensile strength from 47.0 Rkm. to 43.4 Rkm. which corresponded to a 7.7% loss in strength. In the absence of the protective agent succinic diamide dioxime but otherwise under the same conditions the loss in strength amounted to 23.8%.

Example 11 A yarn strand of 60 denier e caprolactam polyamide (Perlon L) was treated for 2 hours at 80 C. in a bath 6 containing 10 g. per liter .of a washing agent of the following composition:

Parts by weight The treatment caused a drop in tensile strength from 43.0 Rkm. to 39.1 Rkm. which corresponded to a 9% loss.

In the absence of the oxime protective agent but otherwise under the same conditions the loss in strength amounted to 19.3%.

This application is a continuation-in-part of application Serial No. 494,554, filed March 15, 1955, now abandoned, which in turn is a continuation-in-part of application Serial No. 419,911, filed March 11, 1954, now Patent No. 2,909,404.

We claim:

A process for treating a synthetic linear polycarbonamide fiber material with an aqueous solution containing an inorganic peroxide textile bleaching agent which comprises treating said fiber material with said aqueous solution containing an inorganic peroxide textile bleaching agent in the presence of water soluble organic compound containing at least one hydroxamic acid group in a quantity suflicient to reduce the loss of strength in the polycarbonamide fibers substantially below that which would be suffered in the absence of said water soluble organic compound.

References Cited in the file of this patent UNITED STATES PATENTS 2,153,416 Frenkel Apr. 4, 1939 2,377,066 Baird May 22, 1945 2,620,325 Langkammerer Dec. 2, 1952 2,661,305 Appleton Dec. 1, 1953 2,730,428 Lindner Ian. 10, 1956 2,909,404 Dithmar Oct. 20, 1959 FOREIGN PATENTS 199,158 Austria Aug. 25, 1958 555,998 Great Britain Sept. 15, 1943 OTHER REFERENCES Yale: Chemical Review, vol. 33, pp. 209-256 (1943). 

